The Pros and Cons of Organic Fertilizers


By his pen, Shakespeare immortalized the words, “That which we call a rose by any other name would smell as sweet.” What makes a rose so special in the first place? How does one draw out that natural beauty?

As landscape professionals, we know that the success of a rose, or any other plant, depends on how it’s cared for. Giving it the right amount of sun and water is a good start, but the difference between an okay landscape and one that would get Juliet’s heart racing lies in the fertilizer.

Chemical or synthetic fertilizer serves as a fast-acting nutritional supplement that goes directly to a plant’s root system, showing results within days of application. For years, our industry has relied on synthetic compounds to provide the ideal blend of nitrogen (N), phosphorus (P) and potassium (K), for our plants.

Have you ever noticed the plants growing in the wild? Look at the forest floor; there are copious bugs and fungi all through the lush undergrowth. What keeps them all in check is a complex biochemical process taking place in the soil, a feeding frenzy of microorganisms competing with one another for dominance. The byproducts of these interactions balance and enrich the nutritional composition of the soil, providing a nearly unshakable foundation for plant life to take root.

Chemical fertilizers don’t provide a supplement for the beneficial activities of microbes in the soil; synthetics actually kill the little guys. Over a long period of time, the use of synthetic fertilizer can lead to plants that are living in dead soil, depending entirely on fertilizer for their nutritional needs.

To illustrate the difference, first consider the way chemical fertilizers work. You add a compound to the soil that dissolves very quickly and is designed to reach a plant’s roots directly. The soil doesn’t play much of a part, other than to hold the plant in place.

Organic fertilizers work in a completely different way. They don’t send soluble nutrients to the roots of the plants; instead, they provide food for the microorganisms that live in the soil. The rich soil becomes the source of plant nutrients, not chemical fertilizers.

“All soils have a limitless supply of plant nutrients,” says Walt Benecki, owner of Walt’s Organic Fertilizer Company in Seattle, Washington. “The problem is, they’re bound up in a form that’s not available to the turfgrass or other plants. When you add organic fertilizer to the soil, it acts like a key to unlock the nutrients. You’re feeding those microorganisms and their population increases, and they will then release the nutrients through their bodily fluids and gases.”

That starts a virtuous cycle (the opposite of a vicious one) in which a growing microorganism population makes the soil richer, and the richer soil, in turn, makes more microorganisms grow. Meanwhile, your lawn is starting to look better, all with the help of a product that just feeds the microbes in the dirt. “When you use organics, a healthy lawn is the primary objective, but it’s a secondary effect,” Benecki says.

Brad Wolfe owns Organo-Lawn, an organic lawn care company in Boulder, Colorado. He recommends that contractors who are interested in adding organic fertilizer programs to their menu of services read up on the subject. Although it’s not complicated in practice, there is a great deal of microbiology going on that’s invisible to the naked eye.

“You have to understand the very complex situation of a living soil,” he says. “In a cupful of soil, there are more than a billion different living organisms competing for resources. No one bacteria or fungus gets out of control. It’s a balanced ecosystem, and when you have that, you don’t have fungus problems with lawns, because everything is always competing with each other. No one species has the ability to take off and overpower the plants.”

Plants that are not in a balanced ecosystem are more susceptible to diseases and pests, mainly because they’re getting only the nutrients and minerals supplied by the chemical fertilizer and nothing from the soil. They might look healthy, but they’re not particularly hardy.

Once you’re onboard with the idea of adding organic fertilizers to your menu of services, the next thing you’ll need to understand is that there is a large variety of products that fall under the classification of ‘organic.’ They differ widely in their composition, best uses and popularity, but they fall into three basic categories: sludge, proteins and composts.

Sludge, quite simply, is liquefied human waste. The fact of the matter is that it can work if it’s used correctly, just like any other fertilizer.

The town of Berkshire, England, has started turning human excrement into high-phosphorus organic fertilizer and expects to save about $350,000 per year by using it. However, not everyone is willing to use sludge, because of the ‘ick’ factor.

Then there’s protein meal. Much of it comes as a byproduct of the meat industry. Feather meal and bone meal, for example, are common ingredients in protein meal organic fertilizers, but some protein also comes from vegetable sources.

Scott Walker, owner of Pleasant Green Grass in Durham, North Carolina, uses granular corn gluten meal as his first application of the year, because it breaks down more slowly in a solid form and is also a powerful pre-emergent weed killer. Wolfe and Benecki also use corn gluten meal in their custom blends because it has a high nitrogen content for an organic fertilizer, and it serves multiple purposes.

Composts tend to be used as top dressings, supplemental to other organic fertilizers in use on lawns. Compost teas are concentrates that stimulate microbial growth in the soil.

“There’s such a variation in organics that you’ve got to know how they’re made,” says Jeff Leuzinger, sales manager for Pearl Valley Organix, a chicken manure fertilizer brand in Pearl City, Illinois. “The right ingredients are key to using organic fertilizer to solve a lawn problem, whether that problem is low growth, pH imbalance or weeds.”

One sticking point about organics is that they cost more. The budgetary adjustment might take some getting used to. To offset this, don’t underestimate your client’s concern for the environment. Some people want to help contribute by being ecologically compliant, and they’re willing to pay more for it.

Putting aside the cost issue, the lawn itself can have a rocky transition to organics, especially if it has been on an aggressive synthetic fertilizer program for a long time. “It’s like being on a drug,” Walker says. “The lawn needs to detox, so to speak.”

During this so-called detoxification period, all manner of weeds, pests and other problems may emerge. This is where educating your client, and encouraging him to be patient, is the most important. You’ll need to explain that if these issues come up after transitioning to an organic fertilizer program, they had always been present, but were masked by the continued use of synthetic fertilizers.

Another issue with maintaining an organic lawn is that you may have to change your watering and mowing practices significantly. Remember, organic fertilizers feed the soil, not the lawn. Everything we’re doing in an organic program is designed to benefit the soil, which in turn will benefit the turf. With that in mind, it’s important to know that, in general, the soil wants drier conditions and higher grass than most people give it.

“I’ve had people say that they’ve tried organics in the past and they didn’t work,” says Wolfe. “I explain to them that watering the lawn properly is the most important aspect of an organic program. When you overwater a lawn, which most people do, the microbes are being drowned. They need air, and when you’re watering improperly, you’re killing the microbial activity.” That microbial activity is, of course, exactly what you’re trying to support in an organic fertilizer program.

Wolfe also mows his lawns higher than he would if he were using synthetic fertilizers. The taller the blades of grass, the deeper the roots grow. When the roots grow deep, they foster the development of a larger bed of microbial activity. That way, the organisms and nutrients penetrate deeper into the soil, giving you more bang for your organic buck.

One final stumbling block for an organic lawn is that even after the landscape has fully transitioned to the new fertilizer program, an increase in the presence of weeds is almost guaranteed. There’s simply no organic solution that’s as effective as a good old chemical herbicide.

However, when it’s all said and done, an organic fertilizer program has a lot to offer. It’s a holistic approach to landscape care that can compete with synthetics, and even outperform them. A robust organic lawn is very resilient to climactic shifts and the threat of disease.

In the end, it’s your call. Shakespeare had the last word on the rose; consider your options for fertilizer programs for turf, and you’ll have the last word on its health.